#### Straight line graphs

 1.1 Y-intercept: (0;-4)   and   X-intercept: (4;0)                     1.2    Y-intercept: (0;3)   and   X-intercept: (-1,5;0) 1.3 Y-intercept: (0;-5)   and   X-intercept: (8;0)                     1.4    Y-intercept: (0;-2)   and   X-intercept: (0,8;0) 1.5 Y-intercept: (0;-8)   and   X-intercept: (-10;0)                  1.6    Y-intercept: (0;6)   and   X-intercept: (4;0)

2.1 Y-intercept is (0;-2)   and   X-intercept is (1;0)                     2.2 Y-intercept is (0;3)   and   X-intercept is (-2;0)
Put in y = mx + c                                                                     Put in y = mx + c
Y-intercept (0;-2) : -2 = m(0) + c                                               Y-intercept (0;3) : 3 = m(0) + c
-2 = c                                                                                         3 = c
y = mx - 2                                                                                 y = mx + 3
(1;0): 0 = m(1) - 2                                                                    (-2;0): 0 = m(-2) + 3
2 = m                                                                                         m = 1,5
y = 2x - 2                                                                                   y = 1,5x + 3

2.3                          y = -2x + 4                                   2.4                          y = -0,8x - 4

3.1    y = x + 4                3.2    y = x - 5                   3.3    y = -2x + 2               3.4    y = -4x - 12
3.5    y = 0,4x - 2            3.6    y = -0,75x + 3          3.7    y = 0,5x - 4              3.8    y = -0,25x - 12
3.9    y = 0,4x - 2          3.10    y = 2x - 3               3.11    y = 5x - 6               3.12    y = -x + 9
3.13    y = -2x + 5           3.14    y = -4x - 7             3.15    y = -3x - 11            3.16    y = 0,4x + 4

4.1    f: y = 0,5x + 2            g: y = 6 - 0,75x   of   y = -0,75x + 6
4.2    P(3,2 ; 3,6)
4.3.1    0,5x + 2 = 0   as   x = -4
4.3.2    0,5x + 2 < 0   as   x < -4
4.3.3    6 - 0,75x = 0   as   x = 8
4.3.4    6 - 0,75x > 0   as   x < 8
4.3.5    0,5x + 2 = 6 - 0,75x   as   x = 3,2
4.3.6    0,5x + 2 < 6 - 0,75x   as   x < 3,2
4.3.7    0,5x + 2 > 6 - 0,75x   as   x > 3,2
4.3.8    0,5x + 2 < 0   AND   6 - 0,75x < 0 : no value of x because
f and g cannot both simultaneously be smaller than zero.
4.3.9    0,5x + 2 > 0   AND   6 - 0,75x > 0 if -4 < x < 8   OR   x can have any value between -4 and 8.

5.1    f: y = x - 3            g: y = 0,5x - 1
5.2    P(4 ; 1)
5.3.1    x = 3            5.3.2    x < 3            5.3.3    x = 2            5.3.4    x > 2            5.3.5    x = 4
5.3.6    x < 4            5.3.7    x > 4            5.3.8    x > 3            5.3.9    x < 2

6.1    f: y = 3 - 2x           g: y = 5 - 4x
6.2    P(1 ; 1)
6.3.1    x = 1,5         6.3.2    x < 1,5         6.3.3    x = 1,25                      6.3.4    x < 1,25            6.3.5    x = 1
6.3.6    x < 1            6.3.7    x > 1            6.3.8    x < 1,25   of   x > 2       6.3.9    1,25 < x < 2

7.1    See the accompanying graph.
7.2    P(1,818 ; 7,273)
7.3.1    x > -4
7.3.2    x > 5
7.3.3    x = 1,818
7.3.4    x > 1,818
7.3.5    -4 < x < 5
7.3.6    x < -4   of   x > 5

8.1    See the accompanying graph.
8.2    P(1 ; -1,5)
8.3.1    x > 1,6
8.3.2    x > -2
8.3.3    x = 1
8.3.4    x > 1
8.3.5    -2 < x < 1,6
8.3.6    x < -2   or   x > 1,6

9.1    C(0;-4)   and   D(4;0)
9.2    y = -2x - 1
9.3    P(1;-3)
9.4.1    x = 4            9.4.2    x > 4                 9.4.3    x < 4
9.4.4    x = -0,5        9.4.5    x > -0,5             9.4.6    x < -0,5
9.4.7    x > 1            9.4.8    -0,5 < x < 4       9.4.9    x < -0,5   or   x > 4
9.4.10    x = -0,5   or   x = 4

10.1    f: y = x - 1      and      g: y = -x - 3
10.2    D(1;0)            and      E(-3;0)
10.3    h: y = 3x - 3
10.4.1    x = 1             10.4.2    x < 1                        10.4.3    x > 1
10.4.4    x = 1             10.4.5    x < 1                        10.4.6    x > 1
10.4.7    x = 1             10.4.8    x = 0                        10.4.9    x < 1
10.4.10    x > 0           10.4.11    x < -3   or   x > 1        10.4.12    x < -3   or   x > 1
10.4.13    -3 < x < 1
10.4.14    no values
10.4.15    any value of x except 1
10.5.1    OE   =   3       10.5.2    OD   =   1      10.5.3    OC   =   1       10.5.4    OB   =   3
10.6.1    EB = 4,243    10.6.2    DB = 3,162    10.6.3    DC = 1,414    10.6.4    EC = 3,162